Effect of fixation time and sample type on tissue biomarker preservation in breast cancer in Cameroon

Abstract

Background: Reliable molecular profiling is essential for the effective management of invasive breast cancer. In the Cameroonian context, there is uncertainty about the factors that influence the preservation of tissue biomarkers for this profiling. The aim of this study was to determine the impact of fixation time and sample type on sample quality for molecular analysis and on the profile of four tissue biomarkers in invasive breast cancer.

Methods: A retrospective analytical study was conducted at the pathology laboratory of Douala Gyneco-Obstetric and Pediatric Hospital. After obtaining research authorization, data from archived histopathology and immunohistochemistry reports of patients with invasive breast cancer from 2017 to 2020 were collected. Statistical analysis was performed using SPSS 25 software, and Chi-square and Fisher's exact tests were conducted. Cramer's V was used to determine the strength of association between categorical variables.

Results: In univariate analysis, sample type and fixation time were statistically significantly associated with sample quality for molecular analysis, with a stronger effect observed for sample type than for fixation time. P-values were adjusted after multivariate analysis, revealing a bias in the association: fixation time. There was no significant association between fixation time and
hormone receptor or Her2 profile, but a correlation was found with the Ki67 proliferation index.

Conclusion: To ensure good molecular profiling, emphasis should be placed on sample type rather than fixation time.